1. Field of the Invention
This invention concerns an optical recording medium that carries out new information recording using parts other than existing information recordable parts, and an entertainment system that employs it.
2. Background of the Invention
Recently there have been various types of optical recording media that employ laser light; among them, FIG. 1 shows an example of a so-called CD-ROM. This CD-ROM 200 has a disk-shape substrate formed of polycarbonate, and it has a structure in which aluminum is deposited by vapor deposition in information recordable parts where pits are formed, and it is protected by a protective layer so that the aluminum vapor deposition parts are embedded. In FIG. 1, data area 200D is formed mainly as the information recordable part.
In manufacturing CD-ROM 200, a process is adopted in which information is recorded by laser light on a resist mask disk, this is developed to make pits, a metal mask is made from a disk master, and then a stamper is made from the mother. FIG. 2A shows the state in which a transparent disk 201S, for example made of polycarbonate, is made with a stamper 203. FIG. 2B shows the state in which a metal film 204 for reflection, made of aluminum, for example, is vapor deposited. FIG. 2C shows the state in which a protective layer 205 is formed so as to embed metal film 204.
When reading the information recordable part of a CD-ROM, laser light is irradiated from below disk 201S shown in FIG. 2C, for reading the presence or absence of pits and reproducing the information.
In a CD-ROM that has a structure and manufacturing process as described above, the playback information required by the user is written into the information recordable part such as data area 200D, and it is read out. But recently, besides this playback information, it has been demanded that additional information be written, such as security information to suppress the appearance of forgery software made by illicitly copying the data recorded on the CD-ROM, and personal information such as the end user""s ID number or the number of his playback device.
It is an object of this invention to provide an optical recording medium in which a new information recording part is formed so that in an optical medium, not limited to a CD-ROM, additionally required information can be written, read, or, if necessary, erased.
Yet another object of the present invention is to provide an entertainment system that employs an optical recording medium on which is formed the above-described information recording part.
The invention that accomplishes the above-described and other objects has the following invention-specified features.
(1) In an optical recording medium on which information is written and read by laser light, a new information recording part is formed in the part other than the information recordable part.
(2) In the above first aspect of the present invention, said new information recording part is at least one of a part inside the lead-in area and outside the lead-out area of the optical recording medium.
(3) In the above first aspect of the present invention, said new information recording part is formed of a material that changes by means of laser light.
(4) In the above first aspect of the present invention, said new information recording part is made so that information recording is done by either reaction or discoloration of a photosensitive material due to irradiation of laser light.
(5) In the above first aspect of the present invention, said new information recording part erases information by uniform reaction or discoloration of a photosensitive material due to irradiation of laser light.
(6) In the above first aspect of the present invention, at least either security information or personal information is recorded on said new information recording part.
(7) In an optical recording medium in which information is written and read by laser light, the laser light that either records, plays back, or erases information of the new information recording part on the part other than the information recordable part is either laser light for reading on the user side or high-output laser light.
(8) An entertainment system is suggested, on which one plays games with an optical recording medium on which information is written and read by laser light, by reading a game program that is recorded on said information recordable part of the optical recording medium on which is formed, on the part other than the information recordable part, a new information recording part.
(9) In the above eighth aspect of the present invention, said new information recording part in the entertainment system records at least either security information or personal information.
(10) In the entertainment system of the eighth aspect, the recording, playback, and erasing of information to said new information recording part is done by either laser light for reading or high-output laser light.